Elastomeric Bitumens
This term refers to to the elastic, rubber-like properties of a material that will stretch when pulled and will return relatively quickly to its original shape when released.
Bitumen used in the manufacture of roofing felts is often modified to enhance its properties.
There are two main polymers used to do this. APP and SBS.
APP (Atactic Polypropolene)
is a by product of the plastics industry and strictly speaking is a plastomeric rather than an elastomeric. The addition of this polymer makes the bitumen resistant to ultra violet light and mechanically very strong. APP performs best in the temperature range between -10c and 145c and is suitable for roofs where there is a degree of foot traffic or loading.
SBS ( Styrene Butadiene Styrene)
on the other hand is rubber polymer and its qualities makes the bitumen elastic and gives it a ‘memory’ so that when it expands or is stretched it will slowly return to near its original shape. SBS performs best in the temperature range between -35c and 100c.
In practice, however, manufacturers use fillers to cut these polymers and so their actual properties may be somewhat less than in their pure form.
Some manufacturers of APP products, have added an amount of SBS to the modifying mix to further improve its performance and give a ‘memory’ to the bitumen.This latest waterproofing technology is called elastoplastomeric! This is a feature we use on all our flat roofs, enabling us to confidently offer such long guarantees.
This bitumen when applied to a polyester base makes a popular, user friendly membrane that has a finely tuned mix of qualities that can be tailor made to suit the local and environmental conditions that exist in differing geographical locations.
More SBS in scandinavia for example where the winter temperatures are often well below freezing and more APP in mediterranean countries that don’t experience frosts but have
This term refers to to the elastic, rubber-
There are two main polymers used to do this. APP and SBS.
APP (Atactic Polypropolene)
is a by product of the plastics industry and strictly speaking is a plastomeric rather than an elastomeric. The addition of this polymer makes the bitumen resistant to ultra violet light and mechanically very strong. APP performs best in the temperature range between -
SBS ( Styrene Butadiene Styrene)
on the other hand is rubber polymer and its qualities makes the bitumen elastic and gives it a ‘memory’ so that when it expands or is stretched it will slowly return to near its original shape. SBS performs best in the temperature range between -
In practice, however, manufacturers use fillers to cut these polymers and so their actual properties may be somewhat less than in their pure form.
Some manufacturers of APP products, have added an amount of SBS to the modifying mix to further improve its performance and give a ‘memory’ to the bitumen.This latest waterproofing technology is called elastoplastomeric! This is a feature we use on all our flat roofs, enabling us to confidently offer such long guarantees.
This bitumen when applied to a polyester base makes a popular, user friendly membrane that has a finely tuned mix of qualities that can be tailor made to suit the local and environmental conditions that exist in differing geographical locations.
More SBS in scandinavia for example where the winter temperatures are often well below freezing and more APP in mediterranean countries that don’t experience frosts but have
